Testimonial Block is creating H2 tags for all the content titles. Where in site styles can I adjust these to be H3?

1. My site is correctly tagged for SEO purposes. I have found 5 additional h2 tags that I don't want. 

2. They are coming from the titles in the Testimonial block.

3. I can't edit site styles anywhere to get these titles to adjust to an h2. I don't want to adjust CSS so does anyone know where to change it? 

4. I tried a workaround, as seen in the screenshot, where I moved the testimonial from the title field to the description field, but I'm still getting the h2 tagging error. 

This is also showing up on my team/bio block with the h2 titles as well 

If you need to change to another tag, you can share link to page, I think I can give some code